Single-cylinder circular knitting machine

Abstract

A single-cylinder circular knitting machine, including a needle cylinder and a circular plate that is arranged above the needle cylinder and coaxially thereto. The circular plate is constituted by two portions, one of which can rotate with respect to the other about a diametrical axis of the circular plate. An actuation device is also provided which acts on command on the portion of the circular plate that can rotate with respect to the other one, in order to move it from a first position, in which it is co-planar with respect to the other portion, to a second position, in which it is arranged so as to face the other portion from below, or vice versa.

What is claimed is: 
     
       1. Single-cylinder circular knitting machine, comprising a needle cylinder and a circular plate arranged above the needle cylinder and coaxially thereto, said circular plate being constructed in two portions, one of which is rotatable with respect to the other about a diametrical axis of the circular plate, an actuation device being provided for acting on command on the first portion of the circular plate to move the first portion between a first position, in which the portion is co-planar with respect to the other portion, and a second position, in which the first portion is arranged in a position which is parallel with and beneath the other portion. 
     
     
       2. Machine according to claim 1, wherein each one of said two portions constitutes half of the circular plate. 
     
     
       3. Machine according to claim 1, wherein said circular plate is mounted on a supporting structure supported by a load-bearing structure of the machine such that said supporting structure is rotatable about an axis of the circular plate. 
     
     
       4. Machine according to claim 3, wherein said actuation device comprises a fluid-actuated cylinder acting on command on said first portion of the circular plate to rotate said first portion about said diametrical axis with respect to the other portion of the circular plate. 
     
     
       5. Machine according to claim 4, wherein said other portion of the circular plate is fixed to said supporting structure. 
     
     
       6. Machine according to claim 5, wherein said first portion of the circular plate is fixed to a pivot supported by said supporting structure so that the first portion is rotatable about the axis that forms said diametrical axis, a gear being keyed on said pivot and meshing with a rack connected to the piston of said fluid-actuated cylinder. 
     
     
       7. Machine according to claim 6, wherein said fluid-actuated cylinder is formed in said supporting structure and is arranged so that an axis of the cylinder substantially coincides with the axis of the circular plate. 
     
     
       8. Machine according to claim 1, wherein a plurality of radial grooves is formed in said circular plate, each groove accommodating at least one hook and one complementary hook slideable on command along the corresponding groove of the circular plate so that tips of the hooks protrude radially from the circular plate or so that the hooks retract into the corresponding groove to take up or release loops of knitting formed by needles of the needle cylinder or to transfer the loops of knitting from the needles of one half of the needle cylinder to the needles of the other half of the needle cylinder. 
     
     
       9. Machine according to claim 8, wherein said hooks and said complementary hooks are provided with heels which protrude from the corresponding groove of the circular plate and are engageable with first actuation cams mounted on a portion of the load-bearing structure of the machine supporting said supporting structure. 
     
     
       10. Machine according to claim 9, further comprising second actuation cams engageable with the heels of the complementary hooks arranged on said first portion of the circular plate facing the other portion of the circular plate from below. 
     
     
       11. Machine according to claim 10, wherein said second actuation cams are connected to an upper end of a product suction duct beneath and facing the circular plate. 
     
     
       12. Machine according to claim 1, wherein said circular plate is movable on command along the axis of the needle cylinder. 
     
     
       13. Single-cylinder circular knitting machine, comprising a needle cylinder and a circular plate arranged above the needle cylinder and coaxially thereto, said circular plate being constructed in two portions, one of which is rotatable with respect to the other about a diametrical axis of the circular plate such that the first portion is movable between a first position, in which the portion is co-planar with respect to the other portion, and a second position, in which the first portion is arranged in a position which is parallel with and beneath the other portion. 
     
     
       14. Machine according to claim 13, wherein each one of said two portions constitute s half of the circular plate. 
     
     
       15. Machine according to claim 13, wherein said circular plate is mounted on a supporting structure supported by a load-bearing structure of the machine such that said supporting structure is rotatable about an axis of the circular plate. 
     
     
       16. Machine according to claim 15, wherein said other portion of the circular plate is fixed to said supporting structure. 
     
     
       17. Machine according to claim 16 further comprising an actuation device for acting on command on the first portion of the circular plate to move the first portion between said first and second positions, and wherein said actuation device comprises a fluid-actuated cylinder acting on command on said first portion of the circular plate to rotate said first portion about said diametrical axis with respect to the other portion of the circular plate, and wherein said first portion of the circular plate is fixed to a pivot supported by said supporting structure so that the first portion is rotatable about the axis that forms said diametrical axis, a gear being keyed on said pivot and meshing with a rack connected to the piston of said fluid-actuated cylinder, and wherein said fluid-actuated cylinder is formed in said supporting structure and is arranged so that an axis of the cylinder substantially coincides with the axis of the circular plate. 
     
     
       18. Machine according to claim 13, wherein a plurality of radial grooves is formed in said circular plate, each groove accommodating at least one hook and one complementary hook slideable on command along the corresponding groove of the circular plate so that tips of the hooks protrude radially from the circular plate or so that the hooks retract into the corresponding groove to take up or release loops of knitting formed by needles of the needle cylinder or to transfer the loops of knitting from the needles of one half of the needle cylinder to the needles of the other half of the needle cylinder, and wherein said hooks and said complementary hooks are provided with heels which protrude from the corresponding groove of the circular plate and are engageable with first actuation cams mounted on a portion of the load-bearing structure of the machine supporting said supporting structure. 
     
     
       19. Machine according to claim 18, further comprising second actuation cams engageable with the heels of the complementary hooks arranged on said first portion of the circular plate facing the other portion of the circular plate from below, and wherein said second actuation cams are connected to an upper end of a product suction duct beneath and facing the circular plate. 
     
     
       20. Machine according to claim 13, wherein said cicircular plate is movable on command along the axis of the needle cylinder.